Critical Layer Penetration in a Cold Z-Pinch Plasma by High-Intensity 10.6 Microns Laser Radiation.
Abstract
The intensity dependence of transmission of high-intensity 10.6 microns laser radiation through an overdense cold Z-pinch plasma has been measured to determine a threshold for transmission. A holographic cinema of plasma evolution, obtained independently of the CO2 laser, provided initial information about the target plasma. An intensity threshold for transmission was measured to be about 2.5 x 10 to the 11 W/sq cm for incidence on the pre-pinch plasma, and 2 x 10 to the eleven W/sq cm for the post-pinch plasma. As the laser intensity was increased above threshold, compression of the transmitted pulse was observed from its incident width of 38 nsec to a transmitted width of 15 nsec at maximum intensity of 4 x 10 to the eleven W/cm. Coincidence measurements between the incident and transmitted pulse indicated the blockage of the first portion of the pulse and subsequent transmission of the remainder. Analysis of the laser-induced shock indicated about 60 to 70 percent energy absorption. Enhanced optical continuum emission from the interaction volume was attributed to plasma heating.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1977
- Accession Number
- ADA050773
Entities
People
- John Goodyear Ackenhusen
Organizations
- University of Michigan